1. Field of the Invention
The present disclosure relates to a wet-type image forming apparatus for forming an image using liquid developer containing toner and carrier liquid.
2. Description of the Related Art
A wet-type image forming apparatus for image formation using liquid developer can use toner having a small particle diameter since scattering of the toner is not problematic and, hence, has an advantage of forming a high-quality image. However, the specific surface area of the toner increases since the toner has a small particle diameter, wherefore the toner tends to be highly charged and adhesion to the surface of a developer bearing member such as a developing roller increases. As a result, a cleaning process of removing the liquid developer remaining on the surface of the developing roller after a development process becomes difficult.
Conventionally, several technologies for facilitating this cleaning process have been proposed. As a first conventional technology is known a wet-type image forming apparatus including a removal assisting unit for weakening cohesive force of toner particles in a liquid developer, the removal assisting unit being arranged upstream of a cleaning blade for removing residual liquid developer from the surface of a developing roller in a rotating direction of the developing roller. A charger or the like for applying an electric field having a polarity opposite to a charge polarity of the toner to neutralize the toner is used as this removal assisting unit. As a second conventional technology is known a wet-type image forming apparatus including a similar charge neutralizing unit for residual developer and a control unit for adjusting an output of the charge neutralizing unit according to an output of a charging unit for charging liquid developer.
However, in some cases, the residual developer could not be satisfactorily removed from the developing roller surface only by applying an electric field for charge neutralization to toner particles in liquid developer.